Perforation machines

ABSTRACT

The present invention relates to a machine for perforating, in the transverse direction, paper webs, such as toilet paper and household paper, and webs of similar material. The main object of the invention is to provide a machine which is simple and safe in its construction and which operates at a very high accuracy and further ensures a perforation without causing any noticeable wearing of the parts of the machine involved in the perforation. The object aimed at has been achieved by shaping the abutment means of a longitudinal border reaching into the movement path of the knifes and outside the periphery of the roller, and an elongated pad extending parallel to the roller axis, said pad at the side turned towards the roller provided with abutment and sliding surfaces, for the knife which are extending in the transverse direction of the pad, said surface arranged with some distance from each other and adapted to rebound when being hit by the knife.

United States Patent {72] Inventor Karl Einar Lage Grettve Lilla Edet.Sweden [2i] Appl. No. 774,234 [22] Filed Nov. 8, i968 [45] Patented July27, 1971 73] Assignee Lilla Edets Pappersbruks Alttiebolag Lilla Edet,Sweden [32] Priority Nov. 9, I967 [33] Sweden [S4] PERFORATION MACHINES2 Clelms,4 Drawing Figs.

[52] [1.8. CI 83/349, 83/562, 83/658, 83/678 [51] Int. Cl 526d 1/56,B26f 1/20 [50] Field of Search 83/678, 348, 349, 343, 315, 562, 561,582. 658

[ S 6] Relerences Cited UNITED STATES PATENTS 2,405,598 8/1946 Miller83/561 X 2,598,820 6/1952 Neese 83/348 X 2,986,058 5/196] Besserdich83/348 3,073,l96 l/l963 Marcalus 83/678 X FOREIGN PATENTS 1,133,9707/1962 Germany 83/678 Primary Examiner-James M. MeisterAttorney-Plumley, Tyner and Sandt ABSTRACT: The present inventionrelates to a machine for perforating, in the transverse direction, paperwebs, such as toilet paper and household paper, and webs of similarmaterial. The main object of the invention is to provide a machine whichis simple and safe in its construction and which operates at a very highaccuracy and further ensures a perforation without causing anynoticeable wearing of the parts of the machine involved in theperforation. The object aimed at has been achieved by shaping theabutment means of a longitudinal border reaching into the movement pathof the knifes and outside the periphery of the roller, and an elongatedpad extending parallel to the roller axis, said pad at the side turnedtowards the roller provided with abutment and sliding surfaces, for theknife which are extending in the transverse direction of the pad, saidsurface arranged with some distance from each other and adapted torebound when being hit by the knife.

PATENTED JUL-27 IBTI SHEET 1 BF 3 KARL EINAR LAGE GRETTVE INVENTOR.

.PATENTEU m2? |97| sum 2 or 3 KARL EINAR LAGE GRETTVE INVENTOR.

PAIENTEnJulzmn 3.595117 SHEET 3 [IF 3 KARL ElNAR LAGE G'RETTVE INVENTQR.

J a my PERFORATHON MACHINES Toilet and household paper is practicallyalways provided with a transverse perforation to facilitate the tearingoff of the paper pieces. This perforation was previously provided as asocalled stitch perforations the paper thereat being moved between tworollers one provided with one or several longitudinal grooves and theopposite one having projecting tooth knife ribs having equally spacedcuts. The knife roller and the notch roller were coupled to gears anddimensioned in such a way that the knives projected down into thenotches in the other roller at rotation.

Nowadays the perforation is performed commonly as a socalled knifeperforation for the reason that this kind of perforation is moreaesthetic. This perforation is provided by means of a rotating pair ofshears. Such a device comprises a strong rotating roller having a numberof projecting knifeblades which usually are somewhat helically arrangedalong the roller and a likewise strong but stationary upper bar havingan adjustable knife comprising a number of sections in order tofacilitate the adjustment. This device gives a good perforation resultif only it is carried out with sufficient stability and freedom ofvibration and is extremely well adjusted. In comparison with the devicefor stitch perforation the machine costs will be very high due to thegreater precision and the weight ofthe machine.

The knife perforation could also be performed by means of a perforationmachine (cf. e.g. the Swedish Pat. No. 31 939) which comprises a rotatedknife roller and a driven counter roller cooperating with the firstroller and being rotated with the same speed, the counter roller beingprovided with peripheral grooves in the mantle surface. The knife rolleris displaced axially back and forth during the rotation. When the paperweb passes between the two rollers, the knives make cuts in that partsof the web which are not situated in front of the grooves in the counterroller. A drawback in this kind of a perforation machine is to be seentherein that it must work with a very high grade accuracy as otherwisethe knives will cut into the counter roller and damage the same or therewill not be obtained any perforation lines at all.

One object of the present invention is to render possible a perfecttransverse perforation by means of simpler devices and without anynotable precision. The invention relates not particularly to machinesfor transverse perforation of paper webs and similar material webs,these machines being of the kind having a rotation knife roller with oneor several knives extending in the longitudinal direction of the roller,said knives cooperating with an abutment means. The main object of theinvention is to be seen therein that the abutment means comprises alongitudinal border extending into the path of the knives outside theperiphery of the roller and an elongated pad situated parallel to theroller axis, this pad being on the side turned towards the rollerprovided with abutment and sliding surfaces for the knives said surfacesextending in the transverse direction of the pad the knives againsttheir surfaces. When the material web is fed between the knife rollerand the abutment pad, the web is pressed by the knives against theabutment and sliding surfacesin the following denoted quite simply,abutment surfaces-on the pad and causes thereby a transverse perforationwhich comprises a transverse row of narrow, notchlike openings in thematerial web situated in the row at a distance from each other whichcorresponds to the distance between adjacent abutment surfaces on thepad.

According to a preferred embodiment of the invention the abutmentsurfaces are glass which, against the action of a pneumatic hose, areindividually rebounding when hit by the knife. in such a device there isnot required any notable precision but the abutment of the knife willalways be sufficient and effective also after a considerable wearing ofthe knife as well as of the glass.

The invention will now be elucidated with reference to the accompanyingdrawings. in the drawings:

FIG. 1 is an end elevation shown partly in cross section of aperforating machine provided with a perforation device according to theinvention,

F IG. 2 shows on an enlarged scale a cross section through theperforation device proper,

F l0. 3 is a side elevation shown in a partial vertical longitudinalsection of the right-hand part of the perforating machine, and

FIG. 43 is a plan view of a border vided with a transverse perforation.

Mounted for rotation between the two vertical stand gables 1 (only oneshown on the drawings) is a horizontal roller 2 having rather long knifeblades 5 clamped by means of the clamping pieces 4 in longitudinalgrooves 3 in the roller 2, said knife blades 5 extending over the wholelength of the roller 2 and reaching with a border portion 6 outside theperiphery of the roller. Cooperating with the knife roller 2 are twoguide rollers 7 covered with soft felt and guiding a paper web 8 from astorage roller (not shown) over the knife roller 2. Extending over theknife roller 2 are two arms 9 which with one end are journaled about ashaft 10 parallel to the knife roller 2. A number of rectangularabutment-means 13 of glass are arranged in a downwards opening groove llin a bar l2 carried in one of the arms 9, these abutment means in thelower position, the operation position, resting with their ends onsupporting ribs 14 along the opening l5 of the groove against the kniferoller 2. At the top of the groove ll there is inserted a bladder or ahose 16 extending along the whole of the groove and comprising anelastic materiaLeg. rubber, said hose to adapted to be connected to asource of compressed air (not shown). The air pressure in the hose 16keeps all the abutment means 13 resiliently against the supporting ribs14. Inserted between adjacent abutment means 13 is a distance piece 17.An adjustment bolt 18 extends through the free end of the arm 9 inquestion and rests with the lower end on the stand gable l and this boltcan be used for adjusting the bar 12 in such a way that the lower borderportions l9 of the abutment means will be situated in the path of theouter borders 6 of the knife blades 5 at the rotation of the kniferoller 2. A piston 21 which is vertically displaceable in a cylinder 20can be used for swinging the arms 9 with the bar 12 in counter clockwisedirection according to FIG. 1 such that the glass abutment means 13: arelifted out of contact with the knife blades 5 such that the insertion ofthe paper web 3 over the knife roller 1. is facilitated.

When the paper web 8 at a lowered bar 12 is with a speed, correspondingto the peripheral speedof the knife roller 2, fed through the machine inthe direction ofthe arrow 22 in FIG. 2, the knife blades 5 press withthe outer borders 6 the paper web up against the abutment surface 23 ofthe abutment means l3, the glass abutment means by the knives beingsomewhat lifted in the groove ll against the action of the pressure inthe hose to to allow the knife blade border 6 to slidingly pass over thesurface 23. The knife blade border 6 tears at its passing along theabutment surface 23 on the abutment means 13 a narrow slot 2d (FlG. 4)in the paper web 3. This web 8 is hereby provided with the perforationline shown in FIG 4 comprising slots 24 and therebetween unbroken parts25 of the paper web 8. The lengths of the slots 24 correspond. to thethickness of the glass abutment means l3 and the: distance betweenneighboring slots 24 corresponds to the thickness of the distance pieces17. The slots 2 5 in the paper web 8 thus are formed on the one hand bythe pressure of the knife blade borders 6 against the glass abutmentmeans 113 and on the other hand by means of a tearing due to the slidingof the blade border 6 along the abutment surfaces 23.

In order to prevent the occurrence ofa toothed border 6 on the knives 5at this wearing as there does not occur any wearing of the border in theinterspace 26 between adjacent abutment means l3, the bar 112 isarranged to slide axially in relation to the knife roller 2. Accordingto the embodiment shown in FIG. 3 the bar U (or the arms 9) is providedwith an elongation arm 27 having a transversely (perpendicularly to thepiece ofa paper web prodrawing plane according to FIG. 3) extending andsomewhat oblong opening 28, an eccenter tap 29 engaging this opening 28from below, said tap 2? being driven for rotation. The value of theeccentricity has been denoted by reference letter 30. The eccenter tap29 is driven via a worm gear 31 from the driving device of the machine(not shown).

At the operation of the machine the bar 12 is, due to the rotatingeccenter tap 29, displaced together with the pad of glass abutment means13 axially in relation to the knife roller 2 at least a distance whichequal to the width of the interspaces 26.

Rather than having the bar 12 displaced axially in relation to the kniferoller 2, the latter may be arranged to be displaced in relation to thebar 12.

The invention has been described in the aforegoing for purposes ofillustration only and is not intended to be limited by this descriptionor otherwise except as defined in the appended claims. Thus, thedifferent parts of the perforation machine may be constructivelymodified in many ways without departure from the inventive idea. Ratherthan abutment means 13 of glass it could be used such of ceramics andhard metal but due to their extreme hardness, wear resistance and lowprice glass is probably to be preferred. In order to obtain the requiredinterspaces 26 between the abutment means 13 at the abutment surface 23there is according to one embodiment of the invention possible to shapethe abutment means l3-instead of using distance pieces l7--with bevclsin such a way that the side surfaces converge down towards its abutmentsurface.

Due to the glass abutment means pad which is under pressure from thepneumatic hose 16 and the different glass abutment means 13 in said padbeing individually loaded, the perforation device is practicallyinsensible for deflections and vibrations such that the machine may beconstructed rather light. The fine adjustment is restricted essentiallyto the adjustment of the pressure in the hose 16. However, the inventionalso embraces a pad serving as a grate for the knife blades 5,

said pad comprising different abutment means which are individuallypressure loaded in another way. Finally, the invention also embraces agrate pad in which the interspaces 26 between the abutment surfaces 19have been obtained e.g. by means of milling in a stationary beam or barof steel or another hard and wear resistant material.

I claim:

1. A machine for transversal perforation of webs of paper or similarmaterial, said machine comprising a rotating knife roller which isprovided with at least one knife extending in the longitudinal directionof the roller, said knife adapted for cooperation with an abutmentmeans, wherein the improvement means ofa longitudinal border adapted toreach into the movement path of said knife and outside the periphery ofthe roller, and an elongated pad extending parallel to the roller axis,said pad at the side turned towards the roller provided with a pluralityof abutment and sliding surfaces for the knife which are extending inthe transverse direction ofthe pad, said surfaces being separated fromone another by separating pieces.

2. A machine for transversal perforation of webs ofpaper or similarmaterial, said machine comprising a rotating knife roller which isprovided with at least one knife extending in the longitudinal directionof the roller, said knife adapted for cooperation with an abutmentmeans, wherein the improvement comprises abutment means of alongitudinal border adapted to reach into the movement path of saidknife and outside the periphery of the roller, and an elongated padextending parallel to the roller axis, said pad at the side turnedtowards the roller provided with a plurality of abutment and slidingsurfaces for the knife which are extending in the transverse directionof the pad, said surfaces being separately bevelled so that they tapertowards their abutment border and said surfaces being separated from oneanother by separation pieces.

1. A machine for transversal perforation of webs of paper or similarmaterial, said machine comprising a rotating knife roller which isprovided with at least one knife extending in the longitudinal directionof the roller, said knife adapted for cooperation with an abutmentmeans, wherein the improvement means of a longitudinal border adapted toreach into the movement path of said knife and outside the periphery ofthe roller, and an elongated pad extending parallel to the roller axis,said pad at the side turned towards the roller provided with a pluralityof abutment and sliding surfaces for the knife which are extending inthe transverse direction of the pad, said surfaces being separated fromone another by separating pieces.
 2. A machine for transversalperforation of webs of paper or similar material, said machinecomprising a rotating knife roller which is provided with at least oneknife extending in the longitudinal direction of the roller, said knifeadapted for cooperation with an abutment means, wherein the improvementcomprises abutment means of a longitudinal border adapted to reach intothe movement path of said knife and outside the periphery of the roller,and an elongated pad extending parallel to the roller axis, said pad atthe side turned towards the roller provided with a plurality of abutmentand sliding surfaces for the knife which are extending in the transversedirection of the pad, said surfaces being separately bevelled so thatthey taper towards their abutment border and said surfaces beingseparated from one another by separation pieces.